Усилители мощности моно — Audio Note Kassai

The Kassai is a mono power amplifier from Audio Note UK, built as a Pure Class A Parallel Single-Ended valve design using a pair of highly regarded 300B directly heated triode valves per channel. Specifically engineered for sonic performance rather than headline technical specifications, the Kassai fulfils every one of Audio Note's Level 4 design criteria - pure Class A operation, zero negative feedback, single-ended output stage, valve rectification and directly heated triode operation - producing what the brand states is a level of performance radically superior to the vast majority of current amplifier designs.

Key specs that matter

Maximum output is 18 watts RMS per channel into either 4 or 8 ohm loads. Input impedance is 100k ohms for the standard configuration, or 600 ohms for the Balanced version. Input sensitivity varies by version - 250mV for Standard, 3.15V for Low Gain (specifically intended for very efficient loudspeakers or a high-gain preamplifier), and 1.6V for Balanced. Channel balance is held within plus-or-minus 0.3dB. The valve complement per pair comprises two 6SN7 driver tubes (one per chassis), four 300B output triodes (two per chassis, run in the parallel single-ended configuration), and two 5U4GB rectifier valves (one per chassis) - the amplifiers ship without valves installed, requiring correct fitting before first use, with Audio Note recommending a dealer handle this given the risk of serious, warranty-voiding damage from incorrect installation. Custom output transformers use copper primary windings with Audio Note's own silver secondary windings, wound on UHiB double-C cores - an uncommon combination of materials at this price point. The Balanced version additionally fits hand-wound balanced XLR input transformers sharing the same copper-primary, silver-secondary construction and premium core material as the output transformers, offering the finest possible signal path from a compatible preamplifier. Internal construction uses copper-foil-in-oil signal capacitors, Tantalum resistors, silver internal wiring and Kaisei electrolytic capacitors in critical circuit areas. At 195 x 205 x 500mm and 20kg per monoblock, maximum power consumption is 200W, and at least 30cm of clearance above each unit is required given the substantial heat the amplifier generates in Class A operation. Built to order with an approximately 8-week lead time.

Sound and use context

Expect a level of performance Audio Note specifically states is engineered around sonic outcome rather than measured specification - the Pure Class A, zero-feedback, directly heated triode topology is a deliberate philosophical choice, prioritising the specific tonal and dynamic characteristics this circuit type is prized for over the higher power figures a feedback-corrected design might otherwise claim.

Pairing

The 18W-per-channel output calls for an efficient loudspeaker to reach satisfying volume, and the Low Gain input sensitivity variant is specifically intended for pairing with very efficient speakers or a preamplifier already delivering considerable gain, while the Balanced version rewards a source or preamplifier with genuine XLR output.

Alternatives

Audio Note's broader monoblock catalogue, including the Quest, Ankoru, Neiro, Shinri, Ginrei, Kageki, Baransu, Kegon and flagship Gaku-On, spans the brand's full Level 3 through Level 5+ hierarchy at escalating price and refinement, worth comparing directly with Audio Note or a specialist dealer to find the specific tier matching a particular budget and loudspeaker pairing.